The politically sensitive matter of naming American warships is getting a deeper look from Congress, where there’s lingering controversy over the Navy’s decision to name vessels after liberal icons César Chávez and John P. Murtha.

A House and Senate committee is expected to order the Navy to explain how it chooses names and why it sometimes deviates from its own policies. Sen. Roy Blunt, R-Mo., inserted a provision in the National Defense Authorization Act that calls for a review of the ship naming process.

The House had been pursuing the matter separately, sometimes led by Rep. Duncan Hunter, R-Alpine, who criticized Navy Secretary Ray Mabus last spring for naming a dry cargo ship after Chávez, the late labor and civil rights leader.

“Naming a ship after César Chávez goes right along with other recent decisions by the Navy that appear to be more about making a political statement than upholding the Navy’s history and tradition,” Hunter said in May.

Mabus’ decision was hailed by Sen. Barbara Boxer, D-Calif., who said in a letter to the secretary that, “Those who have criticized the Navy’s decision to name this ship after César Chávez show a disappointing lack of knowledge of the standards and traditions that are such an important part of United States Navy history.”

Mabus put Chávez’s name on one of the Navy’s T-AKE dry cargo ships, which the Navy said it would name in honor of “famous American pioneers, explorers, and visionaries.”

The Navy secretary is responsible for naming warships, and Mabus defended his decision to honor Chávez in May when he visited General Dynamics NASSCO in San Diego, where the 689-foot vessel is being built.

But anyone can propose the name for a ship, and lawmakers regularly do so. Hunter, a former Marine, wants the Navy to name a ship after Sgt. Rafael Peralta, a San Diego Marine who was nominated for the Medal of Honor for action in Iraq.

The friction over naming involves not only Chávez, but Murtha, the late Democratic congressman from Pennsylvania. Earlier this year, Mabus named an amphibious warship after Murtha, a former Marine who later became one of the most powerful figures in Congress, especially on defense matters.

The decision infuriated some people because Murtha had accused some Marines of “killing innocent people” during an incident in Iraq. There also was controversy because Murtha’s name will be on a San Antonio-class ship. All of the previous vessels in that line have been named either for cities, including San Diego, or place like Somerset County, Pa., and Mesa Verde National Park in Colorado.

The defense bill amendment made by Blunt asks the military to explain whether the current methods for naming ships differs from historical policies and practice, and to explain any variations.

“Rules for giving certain types of ships certain types of names have evolved over time,” Ronald O’Rourke, a national defense specialist for the Congressional Research Service, wrote in a report to Congress. “Attack submarines, for example, were once named for fish, then later for cities, and most recently for states, while cruisers were named for cities, then later for states, and most recently for battles.

“The Navy states that while it ‘has attempted to be systematic in naming ships, like all institutions it has been subject to evolutionary change, and the name sources of the Navy’s ships have not been immune to this change.’’’

O’Rourke adds: “There have been exceptions to the Navy’s ship-naming rules, particularly for the purpose of naming a ship for a person when the rule for that type of ship would have called for it to be named for something else. Some observers in recent years have perceived a breakdown in, or corruption of, the rules for naming Navy ships.

“For example, the three-ship Seawolf class of attack submarines — Seawolf, Connecticut and Jimmy Carter — were named for a fish, a state, and a president, reflecting no apparent rule.”

Joe Kasper, a spokesman for Hunter, said, “There’s no interest on the part of Representative Hunter to give Congress the responsibility of naming every vessel, but the process is worthy of closer examination.

“And there’s absolutely no interest in politicizing the naming of ships. If anything, the process now is what’s motivating people to take a second look at the Navy’s decisions. At 11 different times in the last 20 years, Congress has directed or encouraged the Navy to name a ship after someone in particular. Congressman Hunter’s amendment to the annual defense bills encourages the Navy to name a ship after Sgt. Rafael Peralta, who definitely deserves the honor.”